分离式双箱梁风致振动全过程流场研究
发布时间：2018-08-26 13:36
【摘要】：分离式双箱梁是一种较为新型的大跨度悬索桥主梁断面形式,具有良好的气动稳定性,与传统的整体式箱梁相比,其颤振临界风速较高,但对于涡激振动更为敏感。从现场监测资料可以看出,采用分离式双箱梁断面的某大跨度悬索桥在5m/s至10m/s的风速范围内涡激振动现象较为明显。目前对于诱导分离式双箱梁桥发生风致振动的原因仍没有清晰的解释,尤其是从流场的角度,目前仍缺乏全面、深入的分析。本文对分离式双箱梁悬索桥风致振动全过程进行研究,以某大跨度悬索桥为对象,进行弹性节段模型风洞试验研究。试验采用1:200的几何缩尺比模型,测量了模型在0°风攻角层流风下的风致振动响应特性,并采用粒子图像测速(Particle Image Velocimetry,PIV)系统观测了结构发生涡激共振及颤振时的绕流流场,以研究涡振及颤振过程的绕流场特征。具体研究内容所如下:1.测量结构的静态流场特征,研究不同风攻角下的分离式双箱梁绕流场形态。2.测量结构发生涡激共振时的振动响应特征及绕流场特性,对比不同风速下的振动响应及流场特征,研究流场形态与结构振动的相互作用。3.测量结构发生颤振时的振动响应特征及绕流场特性,对比不同风速下的振动响应及流场特征,研究流场形态与结构振动的相互作用。试验结果显示,分离式双箱梁悬索桥在较低风速下会发生竖向及扭转两个方向的单自由度涡激共振,而竖向和扭转各自存在两个不同的锁定风速范围,结构振动频率均与结构固有的竖向、扭转频率相同;结构在较高风速下会发生竖向、扭转两个自由度的耦合颤振,此时竖向和扭转频率彼此相同,在气动阻尼的影响下又异于结构自身固有频率。通过对结构绕流气流速度场的识别得到了结构风致振动全过程的流场变化,包括旋涡的生成、传递和脱落过程,进而对旋涡特征进行量化计算以分析结构振动和流场之间的相互作用。
[Abstract]:Split double box girder is a new type of long span suspension bridge main girder section form, with good aerodynamic stability, compared with the traditional integral box girder, its flutter critical wind speed is higher, but more sensitive to vortex-induced vibration. From the field monitoring data, it can be seen that the vortex-induced vibration of a long-span suspension bridge with split double box girder section is obvious in the range of wind speed from 5m/s to 10m/s. At present, there is still no clear explanation for the wind-induced vibration of the separated double-box-girder bridge, especially from the point of view of the flow field, there is still a lack of comprehensive and in-depth analysis. In this paper, the wind-induced vibration of a separated double-box-girder suspension bridge is studied. The wind tunnel test of a long-span suspension bridge is carried out with an elastic segmental model. The wind induced vibration response of the model under the wind of 0 掳wind angle of attack is measured by using the geometric scale ratio model of 1: 200, and the flow field around the structure with vortex-induced resonance and flutter is observed by particle image velocimetry (Particle Image Velocimetry,PIV) system. In order to study the characteristics of vortex vibration and flutter around the flow field. The specific contents of the study are as follows: 1. The static flow field characteristics of the structure are measured, and the flow field around the separated double box girder with different wind attack angles is studied. The characteristics of vibration response and flow field around a structure with vortex-induced resonance are measured. The interaction between flow field shape and structure vibration is studied by comparing the vibration response and flow field characteristics under different wind speeds. The characteristics of vibration response and flow field around the structure were measured, and the interaction between the flow field and the structure vibration was studied by comparing the vibration response and the flow field characteristics under different wind speeds. The experimental results show that single degree of freedom vortex-induced resonance occurs in the vertical and torsional directions of the separated double-box-girder suspension bridge under lower wind speed, while the vertical and torsional wind have two different locked wind speed ranges. The vibration frequency of the structure is the same as that of the vertical direction of the structure and the torsional frequency of the structure is the same as that of the structure, and the vertical vibration frequency of the structure is the same as that of the torsional frequency at the higher wind speed, and the coupled flutter of two degrees of freedom is torsional. Under the influence of aerodynamic damping, it is different from the natural frequency of the structure itself. Through the identification of the velocity field of the flow around the structure, the variation of the flow field in the whole process of the wind-induced vibration of the structure is obtained, including the generation, transfer and shedding of vortex. Then the vortex characteristics are quantitatively calculated to analyze the interaction between the structure vibration and the flow field.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3;U448.213
本文编号：2205021
[Abstract]:Split double box girder is a new type of long span suspension bridge main girder section form, with good aerodynamic stability, compared with the traditional integral box girder, its flutter critical wind speed is higher, but more sensitive to vortex-induced vibration. From the field monitoring data, it can be seen that the vortex-induced vibration of a long-span suspension bridge with split double box girder section is obvious in the range of wind speed from 5m/s to 10m/s. At present, there is still no clear explanation for the wind-induced vibration of the separated double-box-girder bridge, especially from the point of view of the flow field, there is still a lack of comprehensive and in-depth analysis. In this paper, the wind-induced vibration of a separated double-box-girder suspension bridge is studied. The wind tunnel test of a long-span suspension bridge is carried out with an elastic segmental model. The wind induced vibration response of the model under the wind of 0 掳wind angle of attack is measured by using the geometric scale ratio model of 1: 200, and the flow field around the structure with vortex-induced resonance and flutter is observed by particle image velocimetry (Particle Image Velocimetry,PIV) system. In order to study the characteristics of vortex vibration and flutter around the flow field. The specific contents of the study are as follows: 1. The static flow field characteristics of the structure are measured, and the flow field around the separated double box girder with different wind attack angles is studied. The characteristics of vibration response and flow field around a structure with vortex-induced resonance are measured. The interaction between flow field shape and structure vibration is studied by comparing the vibration response and flow field characteristics under different wind speeds. The characteristics of vibration response and flow field around the structure were measured, and the interaction between the flow field and the structure vibration was studied by comparing the vibration response and the flow field characteristics under different wind speeds. The experimental results show that single degree of freedom vortex-induced resonance occurs in the vertical and torsional directions of the separated double-box-girder suspension bridge under lower wind speed, while the vertical and torsional wind have two different locked wind speed ranges. The vibration frequency of the structure is the same as that of the vertical direction of the structure and the torsional frequency of the structure is the same as that of the structure, and the vertical vibration frequency of the structure is the same as that of the torsional frequency at the higher wind speed, and the coupled flutter of two degrees of freedom is torsional. Under the influence of aerodynamic damping, it is different from the natural frequency of the structure itself. Through the identification of the velocity field of the flow around the structure, the variation of the flow field in the whole process of the wind-induced vibration of the structure is obtained, including the generation, transfer and shedding of vortex. Then the vortex characteristics are quantitatively calculated to analyze the interaction between the structure vibration and the flow field.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3;U448.213
【参考文献】
相关期刊论文 前1条
1 杨奰昕;葛耀君;项海帆;;平板断面扭弯耦合颤振机理研究[J];工程力学;2006年12期
，本文编号：2205021
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